Recent information suggests that the Mexican Hispanic population in the United States is at high risk for coronary heart disease, Diabetes mellitus, and some site-specific forms of cancer. Other data indicate that sociocultural factors may play a primary role in determining the health status of this population. The most important factors implicated are diet-related knowledge, attitudes, and behaviors, and utilization of medical services. The proposed Phase I study will develop and pretest an integrated set of survey and unobtrusive instruments and procedures to measure and monitor dietary knowledge and behaviors and other important preventive health behaviors in the Mexican Hispanic population. The resulting commercial product will be designed for broad, cost-effective application within this increasingly significant segment of the American population. It will have particular application for the design, baseline assessment, implementation, and longitudinal evaluation of health intervention projects within this group. Proposed Phase II research will apply these instruments on a community-level sample of the Mexican Hispanic population in the context of a randomized intervention for diet modification.